I'm sorry I don't know the brand, but at the range I go to, they have a red "triangular" plastic front rest that seems very versatile.
It is triangular in "cross section", and each "side" has a different basic height from the bench. So you can change the height of the rest, by turning it to one of the three sides.
And on each side, the surface is "stepped", for finer height adjustments! Very cool!
My only complaint is that it is made of normal "slippery" plastic. If I owned one, I'd probably glue something tacky (rubber) to the steps.
Sounds like what you're looking for!